用J2ME在移动设备上实现动画

import java.io.*;

import java.util.*;

import javax.microedition.lcdui.*;

import javax.microedition.midlet.*;

// MIDlet that displays some simple animations.

// Displays a series of birds on the screen and

// animates them at different (random) rates.

public class AnimationTest extends MIDlet

implements CommandListener {;

private static final int BIRD_FRAMES = 7;

private static final int NUM_BIRDS = 5;

private Display display;

private Timer timer = new Timer();

private AnimatedImage[] birds;

private Random random = new Random();

public static final Command exitCommand =

new Command( "Exit",

Command.EXIT, 1 );

public AnimationTest(){;

};

public void commandAction( Command c,

Displayable d ){;

if( c == exitCommand ){;

exitMIDlet();

};

};

protected void destroyApp( boolean unconditional )

throws MIDletStateChangeException {;

exitMIDlet();

};

public void exitMIDlet(){;

timer.cancel(); // turn it off...

notifyDestroyed();

};

// Generate a non-negative random number...

private int genRandom( int upper ){;

return( Math.abs( random.nextInt() ) % upper );

};

public Display getDisplay(){; return display; };

// Initialize things by creating the canvas and then

// creating a series of birds that are moved to

// random locations on the canvas and attached to

// a timer for scheduling.

protected void initMIDlet(){;

try {;

AnimatedCanvas c = new

AnimatedCanvas( getDisplay() );

Image[] images =

loadFrames( "/images/bird",

BIRD_FRAMES );

int w = c.getWidth();

int h = c.getHeight();

birds = new AnimatedImage[ NUM_BIRDS ];

for( int i = 0; i < NUM_BIRDS; ++i ){;

AnimatedImage b = new

AnimatedImage( c, images );

birds = b;

b.move( genRandom( w ), genRandom( h ) );

c.add( b );

timer.schedule( b, genRandom( 1000 ),

genRandom( 400 ) );

};

c.addCommand( exitCommand );

c.setCommandListener( this );

getDisplay().setCurrent( c );

};

catch( IOException e ){;

System.out.println( "Could not

load images" );

exitMIDlet();

};

};

// Load the bird animation, which is stored as a

// series of PNG files in the MIDlet suite.

private Image[] loadFrames( String name, int frames )

throws IOException {;

Image[] images = new Image[frames];

for( int i = 0; i < frames; ++i ){;

images = Image.createImage( name +

i + ".png" );

};

return images;

};

protected void pauseApp(){;

};

protected void startApp()

throws MIDletStateChangeException {;

if( display == null ){;

display = Display.getDisplay( this );

initMIDlet();

};

};

};